Last time I checked, you can. 
I’m thinking by “sacrifice”, you mean suicide, correct? Otherwise, we’re expected to sacrifice quite a few things for the good of all.
My opinion: Yes, as long as one keeps firmly in mind the principle that the needs of the many are best served when the needs of individuals are not unduly trampled. After all, the many are nothing more than a whole lot of ones.
Consider a real-world example: eminent domain. Yeah, it’s a major hot button right now; I’ll get to that in a second. The traditional basis for this is that a community, through its governmental actors, determines that some collective need outweighs an individual’s rights. A city has to have some improvement (a bridge, or a train station, or a hospital, or whatever), and for various reasons the options for siting the improvement are limited. “We need to build this new bridge either here or here, and nowhere else.” As such, the central authority has to assume control of private property to proceed, and eminent domain allows the authority to overrule the owners’ objections in order to build the whatever-it-is. Clearly, in these situations, the needs of the many outweigh the needs of the few or the one.
However: as practiced, the ability to take this option must be subject to certain restrictions, to prevent the authority from abusing its power. The city (or other collective) must make the decision in public, and demonstrate that it represents the shared will of the majority of the community; it can’t be a secret action by a small and insulated cadre. Also, the owner(s) must be fairly compensated for the taking of the property. In general, it must be a difficult course, with high hurdles; it cannot be undertaken casually.
Why? Because the needs of all are best served by ensuring that the needs of the many are balanced against the needs of the few or the one. Sometimes, the city really does need to build a bridge, and really does need to take private property to do it (needs of many > needs of one). But if the city is able to do this too easily, then even though in any given isolated circumstance the needs of the many are being served by the setting aside of the needs of the one, given enough time, a pattern emerges where every individual will be abused.
Lately, this balance has tipped, and eminent domain has become something of a dirty word, because cities, drifting into collusion and corruption with powerful interests, have been using the power to take property from one private individual and give it to another, for the purpose of building a shopping mall, or a ski resort, or some other for-profit enterprise. The city will naturally argue that the collective need of the community is being served by the project (attracting shoppers/tourists who spend money; also, creating jobs, and providing additional tax revenue; etc), and as such the original landowners just have to suck it up. This is creating two problems: the criteria for making the decision to apply eminent domain have been inexorably expanding, becoming more and more dubious; and second, as resentment and resistance increases, the city (or other authority) needs to resort to ever more heavy-handed tactics to push the decision to completion and hold down costs (such as condemning the property in question prior to claiming eminent domain). Individuals, more and more, are getting the shaft, as a legitimate application of authority morphs into an unrecognizable corruption of its original form.
So there’s your example, demonstrating the principle. The needs of the many do outweigh the needs of the few, or the one; but the needs of the many, as a collective of individuals, are best served by guarding against the abuse of any single person or small subset.
I have no problem with self-sacrifice if that’s what the individual in question wants/thinks is right, but it is, and should be, a CHOICE. Placing others’ needs before one’s own is a noble thing to do, but it is not an obligation. I don’t believe it is right for an individual to actively work against society for his own gain, but I don’t believe that said individual should be expected to place the needs of society before his own happiness and well-being, either. We have the ability to evaluate a situation and decide for ourselves what is right. Why, then, should we have to ignore our own convictions for the “greater good?” For that matter, who has the right to decide what is best for society? Shouldn’t it be left to the individuals to decide what is best for themselves (without infringing on the rights of others, of course)?
I’m thinking mostly of large-scale things, such as being asked to sacrifice one’s life, when I write this. It is unavoidable that small sacrifices will have to be made in order for society to function, and while I don’t necessarily believe that those expectations are “right,” I do recognize that a world without them would be wildly unstable at best.
So, my final answer for the OP is: yes and no. Useful, I know.
This does seem to be mostly a Left vs Right thing. It’s amazing how that dichotomy can be so pervasive.
I’m not familiar with the laws in PA - certainly you can here in Texas - but this is basically a function of your state and locality.
Not in my city, for sure.
I, for one, think Spock is full of it. The “common good” is an imaginary beast used to deny the individual his identity and his liberty. What are we if not a group of individuals?
If you want to start talking about “providing for the greatest number of individuals,” like Jeremy Bentham’s nonsense about the felicific calculus, that’s all very well and good for the individual philanthropist, but it is no man’s place to decide which minority will suffer to deliver pleasure to the masses. That is certainly not the function of a just government. The government’s authority and each person’s freedom to act both end at boundaries set by the rights of individuals.
That principle should hold whether it’s the Bush administration trying to claim “public safety” as a justification for secret detentions, torture, and domestic surveillance, the federal government telling people what mind-altering substances they are and are not allowed to use, or some busybody trying to tell me I can’t have a gun or three (dozen) in my home. 
Can the government prohibit you from burning hazardous substances, like plastics or medical waste, just on your side of your property line?
No, I don’t mean suicide at all there.
Who is ‘we’ kimo sabe? 
I don’t expect individuals to sacrifice for the good of all…I expect people to have enlightened self interest myself. I never EXPECT others to sacrifice for me or mine…and that is where I diverge from what is obviously your and others philosophy on this point. It actually sickens me to take such a thing for granted in so cavalier a fashion.
-XT
To be sure. I can put a gun to your head and take your life as well. Does that give me the right?
In the case you bring up this is a good example of what government is good for (one of the few things it IS good for…YMMV of course)…that of acting as an arbiter for the weak against the strong and enforcing policy for that nebulous ‘common good’. Taxes for things like infrastructure we all use, enforcement of things like clean air, water and food, regulation of public lands, mutual defense (which doesn’t include foreign adventures to Iraq and Afghanistan and the like)…those are all examples where it’s in our collective self interest to support a ‘common good’.
-XT
So we don’t need a government at all, except in matters relating to the economy, public health and safety, law enforcement, and the military.
I completely agree.
Therein lies the difference between “enlightened self-interest” and the selfishness of a thug.
Posts like yours is one of the main reasons I love this board so much. 
Bibby
To be sure. Of course, the devil is in the details, ehe?
Well good. I’m glad we agree on the big picture at least.
-XT
Your self-interest or my self-interest?